The electronics industry strives to develop smaller, less expensive and more powerful components that offer more functions than previous models, which in turn, typically requires increased power. Sometimes, a component will utilize auxiliary devices to achieve a desired result or perform an additional function. Auxiliary devices may require a different voltage than the voltage supplied to the primary components. Consequently, an auxiliary power supply is often necessary to provide the correct voltage to these devices.
Auxiliary power is often provided by adding a power supply to the component or equipment. However, drawbacks to adding these power supplies are added heat, weight, volume and increased component cost. Additionally, excess heat generated by the power supply reduces the efficiency and reliability of the component. Also, additional power supplies increase the complexity of the component because of necessary wiring and circuitry. Ultimately, adding power supplies to the component creates characteristics which are detrimental to the industry goal of producing smaller, more efficient electronic components.
The telecommunications industry utilizes electronic components to power devices, such as voice processing and switching equipment. These devices may comprise several different circuit boards that are housed in a common equipment cabinet. Power is typically supplied to all of the circuitry in the device by a single board mounted power module (BMPM). Smaller BMPMs are desired because they consume less space in the cabinet and allow for smaller equipment. Also, more powerful BMPMs can supply power to a greater number of devices and consequently provide increased services to a consumer.
BMPM performance is evaluated according to its power density, which is the ratio of the total power output to the total volume of the BMPM. The industry desires the highest power density attainable or, practically, the smallest BMPM with the largest power output. However, limitations on BMPM efficiency result in excess heat generation as power output increases, which causes inefficiency, reduced reliability and premature failures. With the use of these more powerful BMPMs there is a concurrent need to remove the additional heat generated by the BMPMs.
Currently, finned heat sinks are used to dissipate heat generated by BMPMs. However, conventional finned heat sinks with external air flow are not capable of removing enough heat to allow increases in BMPM power density. Actually, additional heat dissipation requires a larger heat sink, which effectively lowers the BMPM power density.
Many computer applications utilize a heat sink/fan assembly which significantly increases heat dissipation capability. Other methods of cooling are also available. Active heat dissipation, however, requires additional power to operate the cooling equipment. Similar remedies may be utilized by the telecommunications industry but costs and complexity would escalate because an additional power supply will usually be required to operate any auxiliary equipment.
Accordingly, what is needed in the art is a method of providing power to auxiliary components without adding a separate power supply.